Centralize retained message dialog close callbacks

src/legacy_ui_overlay_services.h

@@ -82,4 +82,11 @@ void bind_legacy_click_destroys_node(ButtonT& button, Node& target) noexcept
     };
 }
 
+inline std::function<void(Node*)> legacy_destroy_node_callback(Node& target)
+{
+    return [&target](Node*) {
+        target.destroy();
+    };
+}
+
 } // namespace pp::panopainter

src/node_input_box.cpp

@@ -1,5 +1,6 @@
 #include "pch.h"
 #include "log.h"
+#include "legacy_ui_overlay_services.h"
 #include "node_input_box.h"
 #include "layout.h"
 
@@ -24,7 +25,7 @@ void NodeInputBox::init()
             on_submit(this, m_field_text->m_text);
     };
     btn_cancel = find<NodeButton>("btn-cancel");
-    btn_cancel->on_click = [&](Node*) { destroy(); };
+    pp::panopainter::bind_legacy_click_destroys_node(*btn_cancel, *this);
     m_capture_children = false; // don't capture children events on mouse_capture
 }
 

src/node_message_box.cpp

@@ -1,5 +1,6 @@
 #include "pch.h"
 #include "log.h"
+#include "legacy_ui_overlay_services.h"
 #include "node_message_box.h"
 #include "layout.h"
 
@@ -23,7 +24,7 @@ void NodeMessageBox::init()
             on_submit(this);
     };
     btn_cancel = find<NodeButton>("btn-cancel");
-    on_submit = btn_cancel->on_click = [&](Node*) { destroy(); };
+    on_submit = btn_cancel->on_click = pp::panopainter::legacy_destroy_node_callback(*this);
     m_capture_children = false; // don't capture children events on mouse_capture
 }